John McDougall MD has a very simple weightloss plan for whole food plantbased vegans:
More Greens / Less Grains!
He writes:
I suggest about 1/3 of the meal should be from these low-calorie vegetables [green & yellow]. If you are desperate, then you may push that amount to ½ of your plate (measured by the eyeball). However, be careful that you do not eat so many of these low-calorie foods that your meal plan is no longer satisfying, because then you won’t want to stick with it for the long run.